This invention relates generally to accessories for marine engines, and more particularly to adaptors or attachments for fresh water flushing of marine engines having lower housings such as those found in outboard and stern-drive engines.
It is well known that marine engines operating in contaminated and/or salt water conditions should be periodically flushed with fresh water to reduce contaminant and salt build-up within the water passages of the engine. In conjunction with boats which are regularly removed from the water then, having a means for introducing a supply of fresh water into the engine while it is operating otherwise out of water serves as an excellent preventive maintenance measure.
Until recently, all outboard engines included water intake ports which were positioned in the lower unit and the sides of the housing, in opposing fashion. These water intakes were so positioned at a mid-point in the depth or fore-and-aft dimension of the lower unit to reduce the possibility of foreign objects in the water such as plastic or paper sheet material becoming lodged around the lower unit and impeding water flow into these water intakes. These opposing water intakes lend themselves easily and conveniently to well-known flushing adaptors such as those disclosed in U.S. Pat. Nos. 2,661,631, 3,931,828, 4,108,190 and 4,359,063. All of these devices variously direct water into water intakes which are opposingly positioned in the mid-portion of the lower housing.
However, as small boats are being propelled faster with modern engines, particularly outboard and stern-drive engines of higher horsepower, as the speed of these boats approaches a certain critical speed, the shape of the lower unit, particularly the bulbous leading portion of the lower unit, has had to be redesigned to improve the high speed water penetrability of these housings through the water. It has been found that at these certain higher speeds, standard housing designs cause water separation from the lower housing surface, reducing or eliminating cooling water into these water intakes and also reducing available water flow to the propellers for propulsion.
In conjunction with these radically redesigned lower housings which include extended and sharply pointed forwardly portions for more efficiently travelling through water at high speed, the position of the water intake has therefore also required relocation. Typically, this repositioning of the water intake is to the lower forwardly surface of the bulbous now pointed portion of the lower housing. These water intakes are typically along or disposed symmetrically about the plane passing through the center of the housing and do not lend themselves to convenient fresh water flushing. None of the inventions described above are adaptable to provide a supply of fresh water into these so repositioned water intakes to accomplish this preventive maintenance flushing.
The present invention provides such a flushing adaptor which is adapted to be releasably installable around the forwardly portion of the revised, extended lower unit design and including fitting means positioned therewith so as to introduce a supply of fresh water into and in fluid communication with these newly positioned water intakes. A method for manufacturing these adaptors is also disclosed.